A party's request that the judge dismiss a potential juror from serving on a trial jury by providing a valid legal reason why he shouldn't serve. Potential bias is a common reason potential jurors are challenged for cause -- for example, the potential juror is a relative of a party or one of the lawyers, or admits to a prejudice against one party's race or religion. Judges can also dismiss a potential juror for cause. There is no limit on the number of successful challenges for cause. Compare peremptory challenges.